Disc Player

ABSTRACT

A linear rack gear is formed on the underside of a slide base, and a planetary gear provided in a chassis, which rotates in engagement with this linear rack gear, causes the slide base to move back and forth. When the slide base is located in its disc store position, the planetary gear engages with a first arcuate rack gear formed in the chassis continuously with the linear rack gear and revolves in accordance therewith, whereupon a clamp causes a clamp cam to slide in a lateral direction to move a float base up and down, thereby achieving clamp and release of a disc, so that the disc player can be manufactured at low cost due to a reduced number of parts in excellent production efficiency.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a disc player such as a singledisc player, or a carousel-type disc player capable of playing aselected one of a plurality of discs. More particularly, the inventionrelates to a loading-type disc player having a slide base holding discsthereon and movable back and forth for transferring the discs between anexchange position and a store position.

[0002] Conventional disc players include a carousel type player having arotatable tray for carrying a plurality of medium discs such as CD, DVD,and the like, a desired one of these discs being selected and played.

[0003] Japanese Patent Application Laid-Open Publication No. 5-182335,for example, discloses one such multi-disc player. The multi-disc playerdisclosed in this publication includes a slide base or tray base onwhich a plurality of discs are carried, wherein forward and backwardmovements of the slide base are effected through a planetary gearmechanism in combination with a rack and a substantially U-shapedtoothed gear having connecting tooth, for enabling discs to be exchangedeven during the play of a disc.

[0004] That is, a single motor is used for selectively driving the slidebase and performing a clamping operation of a disc by means of theplanetary gear mechanism. For driving the rotary tray mounted on theslide base, another motor is provided.

[0005] However, the multi-disc player disclosed in the above-mentionedJapanese Patent Laid-Open Publication No. 5-182335 has the problem ofhigh cost, i.e., since a locking mechanism for locking the slide baseextending from a casing during an exchange of discs must be additionallyprovided, the number of components is increased and the cost for theplayer as a whole is high.

[0006] In other words, a disc player is normally provided with abuilt-in push-close mechanism for automatically withdrawing the slidebase upon detection of pressure on the slide base towards the casing.Therefore, if discs are to be exchanged during another disc is beingplayed, for instance, the slide base must be locked in its fullyextended position so that the push-close mechanism will not be operated,because, otherwise, the playing device and the others may be damaged.Thus an additional locking mechanism for achieving this had to beprovided.

SUMMARY OF THE INVENTION

[0007] The present invention has been devised for solving the problemsdescribed above, and an object of the present invention is to provide adisc player which is manufactured at low cost due to a reduced number ofparts.

[0008] To accomplish the above-mentioned object, according to a firstaspect of the present invention, there is provided a disc playercomprising a chassis, a slide base supported on the chassis so as to bemovable in forward and backward directions between a disc exchangeposition and a disc store position, the slide base capable of holding adisc as a recording medium thereon, a clamp mechanism for clamping adisc to be played at a disc play position, and a planetary gearmechanism for selectively causing the movement of the slide base inforward and backward directions and a clamping operation by the clampmechanism with a single drive source. The planetary gear mechanismincludes a sun gear rotatably mounted on the chassis and driven by thedrive source, a planetary gear rotated by a drive force transmitted fromthe sun gear, and a rotary member provided with the planetary gear andmounted on the chassis such as to be rotatable around a center axis ofthe sun gear.

[0009] Then, a linear rack gear is formed on a bottom face of the slidebase, and the slide base is moved in forward and backward directions byrotation of the planetary gear in engagement with the linear rack gear.Further, a first arcuate rack gear is formed in the chassis at aposition so that it locates adjacent the linear rack gear when the slidebase is located at the disc store position so as to allow the planetarygear to engage therewith consecutively from the linear rack gear, and aclamping operation of a disc by the clamp mechanism is performed by arevolving movement of the planetary gear in engagement with the firstarcuate rack gear.

[0010] According to a second aspect of the present invention based onthe first aspect described above, the clamp mechanism comprises a floatbase, one side of which is rotatably mounted on the chassis, and a clampcam for causing the float base to move upwards and downwards. The clampcam is moved by revolving the rotary member having the planetary gear inengagement with the first arcuate rack gear by a drive force from thedrive source for moving the float base to move upwards and downwards toperform a disc clamping operation and a disc releasing operation.

[0011] As an effect according to the first and second aspects of thepresent invention, the first arcuate rack gear is formed in the chassis,and when the slide base is at its disc store position, clamping of adisc is accomplished by revolving the planetary gear in engagement withthis first arcuate rack gear. That is, because the planetary geartoothes with the first arcuate rack gear, which is integrally formed inthe chassis, reaction forces generated during the clamping operation arereceived by the chassis, whereby the clamping operation is performedstably.

[0012] In addition, according to a third aspect of the present inventionbased on the first or second aspect described above, a second arcuaterack gear is formed continuously with the linear rack gear on the bottomface of the slide base, and a linear cam groove is formed on the bottomface of the slide base parallel to the linear rack gear. The rotarymember has a lock pin which is engaged with and guided by the linear camgroove during the slide base is moving. Further, an arcuate lock camgroove is formed continuously with the linear cam groove on the bottomface of the slide base. The second arcuate rack gear and the arcuatelock cam groove have respective radius centers conforming to the centeraxis of the sun gear when the slide base is located at the disc exchangeposition. After the slide base has reached the disc exchange position, afurther rotation of the sun gear causes the rotary member to revolve,with the planetary gear being engaged with the second arcuate rack gear,while the lock pin of the rotary member is in engagement with thearcuate lock cam groove for locking the slide base not to move inforward and backward directions.

[0013] According, then, to a fourth aspect of the present inventionbased on the third aspect described above, the slide base supports arotary tray which is capable of carrying a plurality of discs thereon,the rotary tray being rotated by a drive mechanism and positioned at alocation for playing a selected one of the plurality of discs. Thelinear rack gear includes a first linear rack gear continuing from oneend of the first arcuate rack gear and a second linear rack gearcontinuing from the other end of the first arcuate rack gear. The slidebase is moved by engagement of the planetary gear with either one of thefirst linear rack gear or the second linear rack gear during a clampingoperation being performed by the clamp mechanism, whereas the slide baseis moved by engagement of the planetary gear with the other one of thelinear rack gear and the second linear rack gear during an unclampingoperation being performed by the clamp mechanism. Further, the secondarcuate rack gear is continuously formed with the other of the firstlinear rack gear or the second linear rack gear.

[0014] Also, according to a fifth aspect of the present invention basedon the fourth aspect described above, the first linear rack gear comesto a position adjacent one end of the first arcuate rack gearcontinuously therewith, while the second linear rack gear comes to aposition adjacent the other end of the first arcuate rack gearcontinuously therewith, when the slide base is located at the disc storeposition.

[0015] As an effect according to the third to fifth aspects of thepresent invention, the second arcuate rack gear and the arcuate lock camgroove are formed such that their radius center conforms to the axis ofthe sun gear when the slide base is at is disc exchange position. Theplanetary gear is toothed with the second arcuate rack gear, while thelock pin is engaged with the arcuate lock cam groove by revolving therotary member, for locking the slide base not to move back and forth.Therefore, additional parts for locking a push-close mechanism whichmust be stopped during the play of a disc are not necessary. A reductionin cost is achieved by the reduction in the number of components.

[0016] In addition, according to a sixth aspect of the present inventionbased on any of the third to fifth aspects described above, the lock pinis provided on the rotary member at a position circumferentially offsetat 45 degrees with respect to the planetary gear.

[0017] Then, according to a seventh aspect of the present inventionbased on any of the third to sixth aspects described above, the arcuatecam groove formed continuously with the linear cam groove has a curvedportion in a deformed U shape bulging outwards from the linear camgroove.

[0018] As an effect according to the sixth and seventh aspects of thepresent invention, the lock pin for locking the slide base in theforward and backward directions is mounted on the rotary member at acircumferentially offset position at 45 degrees with respect to theplanetary gear. Therefore, the planetary gear and the lock pin will notbe aligned in a straight line while the slide base is moving, wherebythe planetary gear is toothed with the rack gear without too much play,enabling the slide base to move smoothly.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] These and other objects and advantages of the present inventionwill become clear from the following description with reference to theaccompanying drawings, wherein:

[0020]FIG. 1 is an overall perspective view showing the chassis of adisc player according to one embodiment of the invention, to which aslide base is coupled;

[0021]FIG. 2 is an overall perspective view showing the disc playeraccording to the same embodiment, wherein the slide base is moved to itsdisc store position;

[0022]FIG. 3 is a top plan view of the chassis, which is a primaryconstituent part of this embodiment, from which the slide base has beenremoved;

[0023]FIG. 4 is a perspective view of a rotary member, which is aprimary constituent part of this embodiment;

[0024]FIG. 5 is a bottom plan view of the slide base, which is a primaryconstituent part of this embodiment;

[0025]FIG. 6 is a cross sectional view taken along the arrows A-A inFIG. 3;

[0026]FIG. 7 is a cross sectional view taken along the arrows B-B inFIG. 3;

[0027]FIG. 8 is a cross sectional view taken along the arrows C-C inFIG. 3;

[0028]FIG. 9 is a bottom plan view illustrating the chassis and theslide base extending therefrom;

[0029] FIGS. 10(a) and 10(b) are cross sectional views illustrating theengagement between the chassis and the slide base;

[0030] FIGS. 11(a) and 11(b) are cross sectional views likewiseillustrating the engagement between the chassis and the slide base;

[0031] FIGS. 12(a) and 12(b) are diagrams given in explanation of themovement of the rotary member with respect to the slide base;

[0032] FIGS. 13(a) and 13(b) are schematic perspective views showing therelationship between a clamp cam of a clamp mechanism and a switch gear;

[0033] FIGS. 14(a) through 14(c) are diagrams given in explanation ofthe movement of the rotary member with respect to the slide base;

[0034] FIGS. 15(a) through 15(d) are top plan views showing themovements of the clamp cam of the clamp and the switch gear;

[0035] FIGS. 16(a) and 16(b) are diagrams given in explanation of themovement of the rotary member with respect to the slide base in thisembodiment;

[0036]FIG. 17 is a perspective view showing the details of a mechanismfor driving a rotary tray in this embodiment;

[0037]FIG. 18 is a perspective view likewise showing the details of themechanism for driving the rotary tray in this embodiment in a stateafter being assembled;

[0038]FIG. 19 is a diagram given in explanation of the arrangement forconnecting a flexible cable for supplying power to a motor for drivingthe rotary tray;

[0039]FIG. 20 is a diagram likewise given in explanation of thearrangement for the flexible cable, in which the slide base is moved tothe disc exchange position;

[0040]FIG. 21 is an overall perspective view showing the chassis and theslide base from which the rotary tray has bee removed;

[0041]FIG. 22 is a bottom plan view of a float base;

[0042]FIG. 23 illustrates likewise the bottom of the float base;

[0043]FIG. 24 is a top plan view of the slide base;

[0044]FIG. 25 is a front view of the slide base; and

[0045]FIG. 26 is a bottom plan view of the chassis to which the slidebase is attached.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] Preferred embodiments of the disc player according to the presentinvention will be hereinafter described with reference to theaccompanying drawings. FIG. 1 and FIG. 2 are overall perspective viewsshowing a disc player according to one embodiment of the presentinvention having a chassis and a slide base attached thereto. FIG. 1illustrates a state wherein the slide base 12 is drawn out to a discexchange position, whereas FIG. 2 illustrates a state wherein the slidebase 12 has been moved to a disc store position.

[0047] As illustrated in the drawings, the disc player of thisembodiment includes the chassis 10, the slide base 12, a rotary tray 14,and the like, all of which are normally accommodated within a casing(not shown). The chassis 10 includes therein a player 16 and a clampmechanism 18 for clamping a disc above the player 16.

[0048] The rotary tray 14 is supported on the slide base 12 such as tobe rotatable around an axis 15. A total of, for example, five discreceivers 14A are formed on the rotary tray 14 for holding, for example,five recording media such as discs. Each of the disc receivers 14A has acut-out 14B, so that the slide base 12 does not interfere with theplayer 16 when it is moved thereto, or with the clamp mechanism 18 whenthe disc is clamped above the player 16. The rotary tray 14 is rotatedby a drive motor to be described later, and stopped so as to position aselected disc over the player 16.

[0049]FIG. 3 is a plan view of the chassis 10 from which the slide base12 has been removed. The player 16 is arranged within a float base 20provided in the back of the chassis 10. The float base 20 has a pair ofrotary shafts 20A at the back which are rotatably supported on a mountbase (not shown) in the chassis 10, so that it pivots around the rotaryshafts 20A by the clamp mechanism 18. A disc located in the disc storeposition is clamped above the player 16 by means of a clamp cam 22,which is slidable in right and left directions.

[0050] The float base 20 is provided with a mount piece 20B for mountinga resilient member in the front on the right side. A spring 21 isbridged across the mount piece 20B and a mount piece 10A formed in thechassis 10 so as to absorb the vibration of the float base 20 generatedduring the play of a disc, for example. The clamp mechanism 18 includesa switch gear 23 for causing the clamp cam 22 to slide. The switch gear23 is secured to the bottom of the chassis 10 such as to be rotatable. Arotational drive force is transmitted 10 the switch gear 23 from arotary member 24 as just described hereinafter.

[0051]FIG. 4 illustrates the rotary member 24. The rotary member 24shown in Fig, 4 includes a revolution shaft 24A protruded at its center,and part of the rotary member 24 is cut out. Two reduction gears 29A,29B are fitted in the cut-out portion of the rotary member 24 on oneside thereof by a support shaft 25.

[0052] The revolution shaft 24A is cylindrical and fitted over the topof a support shaft 10D of a sun gear 10C, which is accommodated at thecenter of a recessed bearing 10B formed in the chassis 10 as shown inFIG. 3, and driven by a drive source (not shown). Thus, the revolutionshaft 24A is rotatable with respect to the chassis 10.

[0053] On one side of the support shaft 25 stands a shaft 26 which ishigher than the former. A planetary gear 28A is provided around theshaft 26 on the top, and a transmission gear 29C is fitted beneath theplanetary gear 28A, and another planetary gear 28B beneath thetransmission gear 29C. The transmission gear 29C and the planetary gear28B engage with the reduction gears 29A, 29B, respectively.

[0054] The rotary member 24 is mounted on the chassis 10 by fitting itsrevolution shaft 24A on top of the support shaft 10D of the sun gear10C. Thereupon, the reduction gear 29A engages with the sun gear 10C,whereby rotation of the sun gear 10C is transmitted to the transmissiongear 29C. The rotary member 24 further has a vertically extending lockpin 30 for engagement with a cam groove, to be described later, formedon the back side of the slide base 12.

[0055] The lock pin 30 is offset circumferentially by about 45 degreeswith respect to the center of the planetary gears 28A, 28B. A clamp gear32 is formed partially around the outer circumference of the rotarymember 24 for engagement with the switch gear 23 to be described later.The offset amount of the lock pin 30 with respect to the planetary gears28A, 28B needs not be 45 degrees but may be suitably set.

[0056]FIG. 5 is a bottom plan view of the slide base 12, illustratingthe back side thereof. As shown in the drawing, a first linear rack gear34 and a second linear rack gear 36 are formed in parallel forengagement with the above-mentioned planetary gear 28A. A linear camgroove 38 having straight parts parallel to the first linear rack gear34 and the second linear rack gear 36 is further provided for engagementwith the lock pin 30. The back end of the second linear rack gear 36leads to a second arcuate rack gear 40 continuously.

[0057] The structures for attaching the slide base 12 to the chassis 10will be described next. The chassis 10 is provided, on the tops of itsright and left side walls, with laterally extending guide rails 11, 13along the lengthwise direction for allowing the slide base 12 to moveback and forth thereon. The guide rails 11, 13 have respective parallelouter rails 11A, 13A and inner rails 11B, 13B. The guide rail 13 isformed longer than the guide rail 11.

[0058]FIG. 6 is a cross section taken along the arrows A-A in FIG. 3,FIG. 7 is a cross section taken along the arrows B-B in FIG. 3, and FIG.8 is a cross section taken along the arrows C-C in FIG. 3. As shown inthese drawings, each of the guide rails 11, 13 is formed along thedirection in which the slide base 12 is moved, and extended outwardsfrom the tops of the right and left side walls of the chassis 10.

[0059] A recess 31 is respectively formed in outer rails 11A, 13A forreceiving a guide piece to be described later. The recess 31 is formedwith part of the inner rails 11B, 13B, the corresponding part of theouter rails 11A, 13A being cut away.

[0060]FIG. 9 is a bottom plan view of the chassis 10 and the slide base12 extended therefrom. FIGS. 10(a), 10(b) and FIGS. 11(a), 11(b) arecross sectional views illustrating the positional relationships betweenthe guide rails 11, 13 of the chassis 10 and first guide pieces 15A, 17Aand second guide pieces 15B, 17B of the slide base 12 in mutualengagement. As shown in these drawings, the first guide pieces 15A, 17Aand the second guide pieces 15B, 17B are provided on the underside ofthe slide base 12, extending laterally, and are spaced away from thebottom of the slide base 12, so that they are positioned lower than theguide rails 11, 13 to prevent the slide base 12 from being lifted upduring its back and forth movements.

[0061] The second guide pieces 15B, 17B are formed on right and leftsides respectively, but in asymmetrical arrangement. As can be seen fromFIGS. 10(a), 10(b) and FIGS. 11(a), 11(b), each laterally extendinglength of the second guide pieces 15B, 17B is formed shorter than thatof the first guide pieces 15A, 17A. The slide base 12 moves back andforth with its sliding face 12C sliding against the support face 10E ofthe chassis 10.

[0062] The slide base 12 is coupled to the chassis 10 as describedbelow. The second guide pieces 15B, 17B are brought into engagement withthe guide rails 11, 13 through the recesses 31, 31 respectively formedtherein. The second guide pieces 15B, 17B are asymmetrically located asmentioned above, and the recesses 31, 31 are formed at positionsconforming to these asymmetrical positions of the second guide pieces.

[0063] In this state, when the slide base 12 is moved a certain distancewith respect to the chassis 10 towards the store position as shown inFIG. 9, a latching means (not shown) operates to restrict a forwardmovement of the slide base 12. Thereafter, the second guide pieces 15B,17B do not permit themselves to be disengaged from the guide rails 11,13 through the recesses 31, 31 unless the latching means is released.Meanwhile, the inwardly extending first guide pieces 15A, 17A come intoengagement with the guide rails 11, 13, snugly fitting under therespective inner guide rails 11B, 13B over the outer rails 11A, 13A asshown in FIGS. 10(a), 10(b), whereby the slide base 12 is attached tothe chassis 10.

[0064] When inserting the second guide pieces 15B, 17B into the recesses31, 31 in the guide rails 11, 13, since the first guide pieces 15A, 17Aare located in front of the guide rails 11, 13, they do not obstruct theassembly of the slide base 12 to the chassis 10. The slide base 12 issimply moved towards its store position, engagement with the chassis 10being achieved as illustrated in FIGS. 10(a), 10(b). Since the secondguide pieces 15B, 17B are formed shorter than the first guide pieces15A, 17A in their lateral direction as shown in FIGS. 10(a), 10(b) andFIGS. 11(a), 11(b), they do not reach below the inner guide rails 11B,13B after the assembling of the slide base 12 to the chassis 10.

[0065] A recessed groove is formed between the outer rail 11A and theinner rail 11B and between the outer rail 13A and the inner rail 13Balong the sliding direction of the slide base 12 in the embodimentdescribed above. However, such groove is not essential and also theouter and inner rails may be formed coplanar with each other.

[0066] When assembling the slide base 12 to the chassis 10, as describedabove, the second guide pieces 15B, 17B which extend laterally less thanthe first guide pieces 15A, 17B are first inserted into the recesses 31,after which the slide base 12 is slid. Therefore, as the slide base 12moves forwards and backwards, the first guide pieces 15A, 17A pass overthe recesses 31 smoothly without interference therefrom.

[0067] Moreover, the guide rails 11, 13 on both sides are not arrangedsymmetrically about the centerline but are offset in the lateraldirection, one of the guide rails 11, 13 (guide rail 11) being shorterthan the other. This allows the widthwise dimension between the guiderails 11, 13 to be set wider and provides enhanced freedom of design incomparison to an arrangement in which both guide rails have the samelength.

[0068] FIGS. 12(a), 12(b) are diagrams given in explanation of themovement of the rotary member 24 with respect to the slide base 12. Thedrawings represent top views in perspective of the slide base 12 and therotary member 24 mounted on the chassis 10.

[0069]FIG. 12(a) illustrates a state wherein the slide base 12 is movingforwards (downwards in the drawing) with respect to the chassis 10. Theplanetary gear 28A rotates in engagement with the first linear rack gear34, thereby imparting the forward movement of the slide base 12. At thistime, a rotational drive force is transmitted to the planetary gear 28Afrom the sun gear 10C (not shown in FIG. 12(a)) mounted on the chassis10, through the reduction gears 29A, 29B and the transmission gear 29C.The lock pin 30 of the rotary member 24 moves along in slidingengagement with the linear cam groove 38.

[0070]FIG. 12(b) illustrates a state wherein the slide base 12 hascompletely extended on the chassis 10. The planetary gear 28A at thistime is positioned at the back end of the first linear rack gear 34. Ifthe slide base 12 is pushed in this state, a sensor detects the backwardmovement of the slide base and a built-in push-close mechanism isoperated, the sun gear 10C being reversely rotated to withdraw the slidebase 12 into the casing.

[0071] FIGS. 13(a), 13(b) are schematic perspective views showing therelationship between the clamp cam 22 and the switch gear 23. The switchgear 23 has a transmission gear 23A partially formed to thecircumference thereof, which engages with the clamp gear 32 of therotary member 24 shown in FIG. 4. The switch gear 23 further includes apinion gear 23B which is coaxial with the transmission gear 23A forengaging with a rack 22A of the clamp cam 22. The clamp cam 22 has apair of cam grooves 22B, 22B formed therein, in which a pair of cam pins20C, 20C on the above-mentioned float base 20 are inserted, so thatsliding movements of the clamp cam 22 can impart vertical motion to thefloat base 20 so as to clamp and release a disc.

[0072] FIGS. 14(a) through 14(c) are diagrams given in explanation ofthe movement of the rotary member 24 similarly to FIGS. 12(a), 12(b),illustrating various movements of the rotary member 24 during a clampingoperation of a disc. FIG. 14(a) illustrates a state immediately afterthe slide base 12 has been returned to its disc store position. Thefirst and the second linear rack gears 34, 36 are located near and abovethe first arcuate rack gear 27 formed in the chassis 10, after the slidebase 12 has moved to the disc store position, and the lowermostplanetary gear 28B supported around the shaft 26 is brought intoengagement with the first arcuate rack gear 27.

[0073] Thereupon, the planetary gear 28B engages with the first arcuaterack gear 27 formed in the chassis 10, the lock pin 30 on the rotarymember 24 being guided along an arcuate cam groove 38A, whereby therotary member 24 starts revolving in the direction of the arrow.

[0074] The arcualte cam groove 38A is formed substantially in the shapeof a deformed letter U, bulging further than the distance between theequally spaced linear cam grooves 38, corresponding to the arrangementof the lock pin 30 which is circumferentially offset at 45 degrees withrespect to the planetary gear 28B. This is because, if the arcuate camgroove was simply U-shaped, there would be too much play for theplanetary gear 28B, resulting in unstable movements of the slide base12. In other words, by forming the arcuate cam groove in the deformedU-shape, the planetary gear 28B and the lock pin 30 will not be alignedin a straight line on the cam groove, whereby there is only little playfor the planetary gear 28B.

[0075] When the rotary member 24 reaches a position illustrated in FIG.14(b), its clamp gear 32 toothes with the transmission gear 23A of theswitch gear 23, whereby the pinion gear 23B engages with the rack 22A ofthe clamp cam 22 as shown in FIG. 15(a), causing the clamp cam 22 toslide in the direction of the arrow.

[0076] The clamp cam 22 is continuously moved from one to another of thestates shown in FIGS. 15(b) through FIG. 15(d), as a result of which thecam pins 20C, 20C of the float base 20 are guided along the slantsurfaces of the cam grooves 22B, 22B as shown in FIG. 13(b). Thereby,the float base 20 is rotated upwards around the rotary shafts 20A forclamping a disc. As shown in FIGS. 15(a) through (d), a pair of stoppins 22D are protruded on the underside of the rack 22A, The clamp cam22 is locked so as not to slide further from the state shown in FIG.15(d) by the abutment of the stop pin 22D with an arcuate cam 23C of theswitch gear 23. By this time, the rotary member 24 has revolved to aposition illustrated in FIG. 14(c).

[0077] Since the planetary gear 28B is in engagement with the firstarcuate rack gear 27 integrally formed in the chassis 10, the reactionforces developed with the clamping operation are applied only to thechassis 10, ensuring stable clamping operation. Also, adverse effects ofvibration or the like after the clamping are reduced.

[0078] The clamp cam 22 is provided with a pair of right and leftprojections 22C for moving a sensor switch 33 shown in FIG. 3. Thesensor switch 33 indicates a current clamping state corresponding to itsturning position, the rightmost position indicating a disc-unclampedstate, an intermediate position indicating a clamping operation beingperformed, and a leftwards turned position indicating a disc-clampedstate. The signals indicative of respective states of the clamp cam 22are output from the sensor switch 33 to a controller (not shown).

[0079] Next, the following explains the movement of the rotary member 24when discs on the rotary tray 14 are exchanged during the play of adisc. FIGS. 16(a), 16(b) are diagrams given in explanation of themovement of the rotary member 24 during the disc exchange while theother disc is being played. When the planetary gear 28A rotates inengagement with the second linear rack gear 36 formed on the undersideof the slide base 12 while a disc is being played, the slide base 12 ismoved from the position shown in FIG. 14(c) through the state shown inFIG. 16(a) towards the direction in which it projects from the casing.

[0080] Under a state illustrated in FIG. 16(b) wherein the slide base 12has reached its disc exchange position where it is completely extendedfrom the casing, the radius center of an arcuate lock cam groove 38B andthat of the second arcuate rack gear 40 conform to the axis of the sungear 10C (not shown in FIG. 16(b)).

[0081] Further rotation of the sun gear 10C causes the planetary gear28A to revolve in engagement with the second arcuate rack gear 40, whilethe lock pin 30 slides into the arcuate lock cam groove 38B, as a resultof which the slide base 12 is kept in position not to move back andforth. Accordingly, the slide base 12 does not allow itself to be pushedback into the casing, and the push-close mechanism is not activated. Inthis way, parts for locking the push-close mechanism which had to beadditionally provided in the prior art are dispensed with, leading to areduction in the number of components.

[0082] The arcuate lock cam groove 38B is curved outwards correspondingto the position of the lock pin 30 for the reasons similar to those forthe above-described arcuate cam groove 38A.

[0083] Next, a drive mechanism for rotating the rotary tray 14 will bedescribed. The drive mechanism 42 for the rotary tray 14 is provided onthe backside of the rotary tray 14 as shown in FIG. 17. FIG. 17 and FIG.18 are perspective views illustrating the details of the drive mechanism42. As shown, the drive mechanism 42 is composed of a motor holder 44, amotor 46, a worm gear 48, and the like. The motor 46 connected to aflexible cable to be described later is secured to a motor mount piece44A of the motor holder 44, and the rotary shaft 46B projects upwards,at the top end of which a pulley 46A is held therearound.

[0084] The motor holder 44 has a socket 44B for mounting the worm gear48. The socket 44B comprises a support hole 44C into which a lower shaft48A of the worm gear 48 is inserted, and a cut-out 44D for supporting anupper shaft 48B of the worm gear 48. A pulley 48C having a largerdiameter than the pulley 46A of the motor 46 is held around the uppershaft 48B. The worm gear 48 toothes with a gear (not shown) provided inthe rotary tray 14 and transmits the rotation of the motor 46 to therotary tray 14, thereby rotating the same.

[0085] The drive mechanism 42 for the rotary tray 14 is assembled in thefollowing procedures. First, the lower shaft 48A of the worm gear 48 isinserted into the support hole 44C of the socket 44B, while the uppershaft 48B of the worm gear 48 is fitted into and abutted against thecut-out 44D. A rubber belt 50 is then stretched between the pulleys 46A,48C, so that the upper shaft 48B of the worm gear is pressed against thecut-out 44D by the tension of the rubber belt 50. Accordingly, the wormgear 48 does not come off as long as the rubber belt 50 is provided.

[0086] Thus the worm gear 48 can be mounted simply by fitting its uppershaft 48B to the socket 44B and providing the rubber belt 50. In thisway, the labor involved in the assembling operation is saved and thenumber of components reduced, whereby a reduction in production cost isachieved.

[0087]FIG. 19 and FIG. 20 are diagrams given in explanation of thearrangement for connecting a flexible cable 52 provided for supplyingpower, and the like, to the motor 46 for driving the rotary tray 14. Asshown in these drawings, the casing 54 accommodates therein the slidebase 12, the rotary tray 14, the player 16, and the like. The player 16is mounted on the chassis 10 (not shown in FIGS. 19 and 20). The wiringfor power supply and control from the player 16 to the motor 46 isaccomplished with the flexible cable 52.

[0088] When the slide base 12 is located in its disc store positionshown in FIG. 19, the flexible cable 52 is bent at a position denoted X,which is ahead of one end 52A and the other end 52A thereof. In thisway, the player 16 and the flexible cable 52 do not interfere with eachother, while the space within the chassis 10 is effectively utilized forpermitting the flexible cable 52 to be moved freely. Thus the overallsize of a disc player including the casing 54 can be reduced, and thelength of the flexible cable 52 can be made to a minimum.

[0089] When the slide base 12 is located at its disc exchange positionextending from the casing 54 as shown in FIG. 20, the motor 46 and theflexible cable 52 connected thereto remain within the casing, and theconnection joint therebetween on the slide base is prevented from beingexposed to the outside. Furthermore, as shown in FIG. 21, a plurality ofhooks 56 for holding the flexible cable 52 (only two shown in thedrawing) are provided on the bottom of the chassis 10 as required, so asto prevent such unstable movements of the flexible cable 52 within thecasing 54 that the cable touches and separates from the chassis 10randomly.

[0090]FIG. 22 and FIG. 23 are bottom plan views of the float base 20.Since the player 16 and the others are mounted on the float base 20, oneend 58A of the flexible cable 58 is connected to the bottom of the floatbase 20 for input/output of control signals with respect to the player16 and the like and for power supply thereto from a circuit substrate(not shown).

[0091] A bending piece 60 formed in the shape of a hook is provided inthe front part on the bottom of the float base 20. The bending piece 60includes a lateral piece 60A and a longitudinal piece 60B, which arerespectively formed with a certain clearance between themselves and theunderside 20D of the float base 20 so as to permit the flexible cable 58to pass therethrough. In other words, the bending piece 60 is attachedto the underside of the float base 20 at the intersection between thelateral piece 60A and the longitudinal piece 60B.

[0092] The bending piece 60 is used mainly for the purpose of enhancingproduction efficiency, i.e., it is used for folding the flexible cable58 at a given location so as to allow itself to be accommodated at apredetermined position on the underside of the float base 20 so as tosave the labor for measuring the flexible cable 58 each time todetermine the position at which it should be folded during theproduction thereof.

[0093] More specifically, the bending piece 60 is used during themanufacture of the disc player as described below. First, the flexiblecable 58 is passed through the clearance between the lateral piece 60Aand the underside 20D of the float base 20 as shown in FIG. 22. Then,the flexible cable 58 is laterally folded back as indicated by thedash-single-dot line in FIG. 22 and passed through the clearance betweenthe longitudinal piece 60B and the underside 20D of the float base 20for determining a folding position of the flexible cable 58.

[0094] Next, the flexible cable 58 which has been folded in accordancewith certain dimensions is released from the bending piece 60, turnedover at one end 58A in the reverse direction as shown in FIG. 23, andpassed through original hold pieces 62A, 62B provided at a correspondingmounting location of the cable 58. In this way, the flexible cable 58 isattached to the float base. The bending piece 60 provided on the bottomof the float base 20 thus facilitates measuring of a folding position ofthe flexible cable 58 and bending of the same, and contributes toenhancement of the production efficiency.

[0095]FIG. 24 is a top plan view of the slide base 12 from which therotary tray has been removed, FIG. 25 is a front view of the slide base12 shown in FIG. 24, and FIG. 26 is a bottom plan view of the chassis 10to which the slide base 12 is attached. As shown in these drawings, apair of engagement holes 12B, 12B are opened in a front end wall 12A ofthe slide base 12. These engagement holes 12B are located at positionsso as to receive the distal ends 19C, 19D of the guide rails 19A, 19B ofthe chassis 10, when the slide base 12 is moved to its disc storeposition, as shown in FIG. 26.

[0096] Thus the slide base 12 at its disc store position is preventedfrom being lifted, and therefore rattling of the slide base 12 isprevented.

[0097] Although the embodiment of the invention has been described aboveby way of example as a so-called carousel-type disc player capable ofaccommodating a plurality of discs, it should be noted that the presentinvention is applicable also to a single disc player.

[0098] While there has been described what are at present considered tobe preferred embodiments of the present invention, it will be understoodthat various modifications may be made thereto, and it is intended thatthe appended claims cover all such modifications as fall within the truespirit and scope of the invention.

What is claimed is:
 1. A disc player comprising: a chassis; a slide basesupported on the chassis so as to be movable in forward and backwarddirections between a disc exchange position and a disc store position,the slide base capable of holding a disc as a recording medium thereon;a clamp mechanism for clamping a disc to be played at a disc playposition; a planetary gear mechanism for alternatively causing themovement of the slide base in forward and backward directions and aclamping operation by the clamp mechanism with a single drive source,said planetary gear mechanism including a sun gear rotatably mounted onsaid chassis and driven by said drive source, a planetary gear rotatedby a drive force transmitted from said sun gear, and a rotary memberprovided with said planetary gear and mounted on said chassis such as tobe rotatable around a center axis of said sun gear; a linear rack gearformed on a bottom face of said slide base, said slide base being movedin forward and backward directions by rotation of said planetary gear inengagement with said linear rack gear; and a first arcuate rack gearformed in said chassis at a position such that it locates adjacent saidlinear rack gear when said slide base is located at the disc storeposition so as to allow said planetary gear to engage therewithconsecutively from the linear rack gear, a clamping operation of a discby said clamp mechanism being performed by a revolving movement of saidplanetary gear in engagement with the first arcuate rack gear.
 2. Thedisc player according to claim 1 , wherein said clamp mechanismcomprises a float base, one side of the float base being rotatablymounted on said chassis, and a clamp cam for causing said float base tomove upwards and downwards, and wherein said clamp cam is moved byrevolving said rotary member having said planetary gear in engagementwith said first arcuate rack gear by a drive force from said drivesource for causing said float base to move upwards and downwards toperform a disc clamping operation and a disc unclamping operation. 3.The disc player according to claim 1 or 2 , further comprising a secondarcuate rack gear formed continuously with said linear rack gear on thebottom face of said slide base, a linear cam groove formed on the bottomface of said slide base parallel to said linear rack gear, said rotarymember having a lock pin being engaged with and guided by said linearcam groove during the slide base is moving, and an arcuate lock camgroove formed continuously with said linear cam groove on the bottomface of said slide base, wherein said second arcuate rack gear and saidarcuate lock cam groove have respective radius centers conforming to thecenter axis of said sun gear when the slide base is located at the discexchange position, wherein a further rotation of the sun gear causessaid rotary member to revolve, with said planetary gear being engagedwith said second arcuate rack gear after the slide base has reached thedisc exchange position, while said lock pin of the rotary member is inengagement with said arcuate lock cam groove for locking said slide basenot to move in forward and backward directions.
 4. The disc playeraccording to claim 3 , wherein said slide base supports a rotary traybeing capable of carrying a plurality of discs thereon, said rotary traybeing rotated by a drive mechanism and positioned at a location forplaying a selected one of said plurality of discs; said linear rack gearcomprises a first linear rack gear continuing from one end of said firstarcuate rack gear and a second linear rack gear continuing from theother end of said first arcuate rack gear, said slide base being movedby engagement of said planetary gear with either one of said firstlinear rack gear or said second linear rack gear during a clampingoperation being performed by the clamp mechanism, whereas said slidebase being moved by engagement of said planetary gear with the other oneof said linear rack gear and said second linear rack gear during anunclamping operation being performed by the clamp mechanism; and saidsecond arcuate rack gear being continuously formed with said other gearof said first linear rack gear or said second linear rack gear.
 5. Thedisc player according to claim 4 , wherein said first linear rack gearcontinuously extends from one end of said first arcuate rack gear, whilesaid second linear rack gear continuously extends from the other end ofsaid first arcuate rack gear, when said slide base is located at thedisc store position.
 6. The disc player according to any one of claims 3to 5 , wherein said lock pin is provided on said rotary member at aposition circumferentially offset at 45 degrees with respect to saidplanetary gear.
 7. The disc player according to any one of claims 3 to 6, wherein said arcuate cam groove formed continuously with said linearcam groove has a curved portion in a deformed U shape bulging outwardsfrom said linear cam groove.